Recreating Some Early Work in Chemical Spectroscopy: A Freshman Chemistry Laboratory Exercise An experiment utilizing an original account of the spectra-analytical work of Bunsen and Kirchhoff has been developed for use with freshman chemistn. students. The emeriment is desimed to introduce students to the use of a prism spectrometer in flame analysis, to put them;n contact with an original account of researcli, and to permit them to recreate experiments of great historical importance. The student handout for this experiment contains a brief historical background and approximately 75%of an original account of Bunsen and Kirchhoff's work.',2 The original text is clearly written, and brighter students might be able to reproduce the experiments without further information. A procedure is included in the handout, however, which explains specifically what students are required to do in the two laboratory periods scheduled for the exercise. Student activities include (a) purification of a barium chloride sample for spectral analysis, (h) mapping of the solar spectrum and major Fraunhoffer lines, (c) observation of the flame spectra of known and unknown samples of Group IA and Group IIA chlorides, and (d) spectral analysis of aii. containing suspended potassium chloride. data bv waveleneth: Bunsen and Kirchhoff did not soecifv . soectral . .. . correlation of data with Fraunhofer lines was utilized. In this experiment, students folluw the same procedure for analyal* of their spectral sampler. Special thanks are extended tu the National Science Fuundatlon, lo Dr. Stephen Hush for the inspiration to develop this experiment received nt a Chautauqua {hurt Cuursr for Cullege Tearhcrr, and t o Mr. Greg Matthrns, a student. for his assistance in prepaiing and testing this laboratory exercise. Copies of the eaperiment are available from the author for production costs. ~
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'Bunsen, R. and Kirchhoff, G., Phil. Mag., 20,89 (1860).
Farber, Edward, "Milestones of Modern Chemistry," Basic Books, Inc., New York, 1966, pp. 15-25. Leslle C. Smedley, Jr. Bethany College Bethany. WV 26032
24
Journal of Chemical Education
